FIG. 5 shows a typical prior art communication system consisting of a fixed network FN and a public land mobile network PLMN. As is well known, a PLMN can provide to the user or subscriber stations MS1, MS2, . . . MSn, a wide range of services and facilities including some that are specific to mobile situations. The PLMNs to which the present invention is applicable comprise the following mobile communication systems:
i) a global system for mobile communications GSM (e.g. GSM 900 MHz; D1 and D2 mobile networks in Germany); PA1 ii) a digital cellular system DCS (DCS 1800 at 1800 MHz; e.g. the E-plus mobile network in Germany); and PA1 iii) a personal communications system PCS (e.g. the PCS 1900 MHz personal communication services in the USA). PA1 i) an integrated services digital network ISDN; PA1 ii) a packet switched public data network PSPDN. PA1 i) a user-network digital interface; PA1 ii) a standardised output signalling protocol supported between the user and the network, enabling the generation and transport of compatibility information. This compatibility information is used for compatibility checking and terminal/function/service selection; and PA1 iii) a standardised output signalling protocol supported within the fixed network. This signalling protocol enables the transport of compatibility information for compatibility checking and terminal/function/ service selection at the user-network interface as well as an interworking function selection. PA1 i) ISDN User Part (ISUP); PA1 ii) Mobile Application Part (MAP). PA1 the limited user rates currently provided by digital mobile systems, i.e. the maximum access user rate of 9.6 KBit/s on the traffic channels; PA1 the fixed ISDN network could not provide, until recently standardised, a multirate scheme to handle and maintain the integrity of more than one ISDN channel per call. PA1 to provide a communication system, a mobile services switching center and a method that allow the establishing of multi-dialogue calls in digital mobile networks between two mobile stations or between a mobile station and a subscriber to the fixed network. PA1 a) at least one first communication channel provided between the first subscriber station and the Mobile Services Switching Center; PA1 b) at least one second communication channel provided between the second subscriber station and the Mobile Services Switching Center; wherein PA1 c) the Mobile Services Switching Center comprises a mapping means for performing said multi-dialogue communication by PA1 a mapping means for performing the multi-dialogue communication by setting up a requested number of concurrent single-dialogues on a corresponding number of the second communication channels and mapping said requested number of single-dialogues as a single call on the second communication channels onto said at least one first communication channel. PA1 a) sending a multi-dialogue call set-up message from the first subscriber station to said Mobile Services Switching Center indicating the number of concurrent single dialogues to be set up; PA1 b) receiving said multi-dialogue call set-up message in the Mobile Services Switching Center and identifying the types of said requested single dialogues; and PA1 c) successively assigning said types of requested single dialogues to a corresponding number of second communication channels between the Mobile Services Switching Center and the second subscriber station; and PA1 d) mapping said requested number of single-dialogues on said second communication channels onto at least one first communication channel between the first subscriber station and the Mobile Services Switching Center. PA1 a) at least one first communication channel provided between the first subscriber station and the Mobile Services Switching Center; PA1 b) at least one second communication channel provided between the second subscriber station and the. Mobile Services Switching Center; wherein, PA1 c) the Mobile Services Switching Center comprises a mapping means for performing said multi-dialogue communication by PA1 a) at least one first communication channel provided between the first subscriber station and the Mobile Services Switching Center; PA1 b) at least one second communication channel provided between the second subscriber station and the Mobile Services Switching Center; wherein PA1 c) the Mobile Services Switching Center comprises a mapping means for performing said multi-dialogue communication by PA1 a) at least one first communication channel provided between the first subscriber station and the Mobile Services Switching Center; PA1 b) at least one second communication channel provided between the second subscriber station and the Mobile Services Switching Center; wherein PA1 c) the Mobile Services Switching Center comprises a mapping means for performing said multi-dialogue communication by PA1 a) at least one first communication channel provided between the first subscriber station and the Mobile Services Switching Center; PA1 b) at least one second communication channel provided between the second subscriber station and the Mobile Services Switching Center; wherein PA1 c) the Mobile Services Switching Center comprises a mapping means for performing said multi-dialogue communication by PA1 a) sending a multi-dialogue call set-up message from the first subscriber station to said Mobile Services Switching Center indicating the number of concurrent single dialogues to be set up; PA1 b) receiving said multi-dialogue call set-up message in the Mobile Services Switching Center and identifying the types of said requested single dialogues; and PA1 c) successively assigning said types of requested single dialogues to a corresponding number of second communication channels between the Mobile Services Switching Center and the second subscriber station; and PA1 d) mapping said requested number of single-dialogues on said second communication channels onto at least one first communication channel between the first subscriber station and the Mobile Services Switching Center; wherein PA1 a) sending a multi-dialogue call set-up message from the first subscriber station to said Mobile Services Switching Center indicating the number of concurrent single dialogues to be set up; PA1 b) receiving said multi-dialogue call set-up message in the Mobile Services Switching Center and identifying the types of said requested single dialogues; and PA1 c) successively assigning said types of requested single dialogues to a corresponding number of second communication channels between the Mobile Services Switching Center and the second subscriber station; and PA1 d) mapping said requested number of single-dialogues on said second communication channels onto at least one first communication channel between the first subscriber station and the Mobile Services Switching Center; wherein PA1 a) sending a multi-dialogue call set-up message from the first subscriber station to said Mobile Services Switching Center indicating the number of concurrent single dialogues to be set up; PA1 b) receiving said multi-dialogue call set-up message in the Mobile Services Switching Center and identifying the types of said requested single dialogues; and PA1 c) successively assigning said types of requested single dialogues to a corresponding number of second communication channels between the Mobile Services Switching Center and the second subscriber station; and PA1 d) mapping said requested number of single-dialogues on said second communication channels onto at least one first communication channel between the first subscriber station and the Mobile Services Switching Center; wherein
A call establishment between mobile stations may take place through a fixed network FN connected to the PLMN via a transmission channel CC2. Alternatively, the two mobile stations may also communicate without the aid of a FN, namely through one or several MSCs within the PLMN. The fixed network FN comprises a number of exchanges EX1, EX2 to which are connected the individual subscriber stations ST1, ST2, . . . STn. The fixed network provides to the subscribers also a wide range of services and facilities at anyone determined access point. The invention is for example applicable to any of the following fixed networks:
The interworking between the FN and the PLMN is known in the prior art and detailed in various GSM technical specifications, for example: 02.01: Principles of telecommunication services supported; 02.02: Bearer Services supported by a GSM PLMN; 02.03: Teleservices supported by a GSM PLMN; 04.08: Mobile Radio Interface Layer 3;07.01: General on Terminal Adaptation functions (TAF) for Mobile Stations (MS); 09.07: General requirements on interworking between the Public Land Mobile Network (PLMN) and the Integrated Services Digital Network (ISDN) or Public Switched Telephone Network (PSTN). Furthermore, ITU specifications describe network interface specifications for the call set-up and call control, namely: Specifications of Signalling System No. 7 Recommendation Q.763-Formats and Codes; Q.931: DSS1-ISDN User Network interface layer 3 specifications for basic call control.
Although explained in the aforementioned documents, hereinafter the general entities of a communication system shown in FIG. 5 are briefly explained. One of the most important fixed networks FN currently being used is the integrated services digital network ISDN, which provides the following features:
Of course, the communication between the different units in the communication system in FIG. 5 requires the set-up of network protocols, for example the Signalling System No. 7 is used to transport these protocols. Important network protocols usable with the invention are: